Nongfu Spring lashed out at the Consumer Council on Tuesday, accusing the watchdog of affecting its reputation by making what is said were biased comments towards its water content.

The company demanded an apology and clarification from the watchdog.

The Consumer Council was following up on a lawyer's letter issued by Nongfu Spring, a day after the watchdog revealed its test results on 30 bottled water brands.

Nongfu Spring said the watchdog wrongly categorised its product, applied an incorrect testing standard, and claimed the findings were misleading.

It also claimed the council's findings caused panic among Hong Kong and mainland consumers, and had caused "massive" damage to its brand.

Nongfu Spring stressed it would take further action unless the watchdog apologised and clarified its test results.

The council confirmed it had received a letter issued by Nongfu Spring's lawyer.

It maintained its analysis showed all samples of bottled water it tested were safe to drink.